My dear one,
How are you? And how is your cancer?

I do not know what you are thinking, but Dharma practitioners, especially Mahayana practitioners, look at life-threatening diseases as very fortunate to have.

This is because by having that disease, you are able to practice Dharma, especially tonglen, taking others’ suffering and giving your happiness to others who are numberless. You are taking the suffering of numberless others to only one, yourself, into your heart, and giving it to the self-cherishing thought, your greatest demon, which caused you oceans of samsaric suffering from beginningless rebirth, now and in the endless future.

Destroy the great demon, the self-cherishing thought! Not only is it stopping you from achieving enlightenment, it is also harming numberless sentient beings, who do not achieve enlightenment. So, destroy this greatest demon, this mara. By destroying it you are able to generate bodhicitta, which brings all happiness and enlightenment for you and for numberless sentient beings—hell beings, hungry ghosts, animals, humans, suras and asuras—all the six realm beings.

Just as Tibetans recite OM MANI PADME HUM all day long, please think:

By my experiencing this cancer, may all the kind mother sentient beings—all the numberless hell beings, numberless hungry ghosts, numberless ants, numberless fish in the ocean, numberless worms in the ground, numberless insects in the grass and bushes, numberless insects in the trees and the sky—be free from all the sicknesses, spirit harm, negative karma and defilements, and may they achieve buddhahood, the total cessation of mistakes and completion of realizations, the peerless happiness.

Here I have a little bit elaborated on the animals, but you should know the essence:

By my experiencing cancer, may all the kind mother sentient beings be free from all sickness, spirit harm, negative karma and defilements, and may they achieve buddhahood.

Recite this prayer day and night, just as Tibetan people recite OM MANI PADME HUM.

You should know that all the buddhas and bodhisattvas are helping you with loving kindness and compassion.

With much love and prayer ...